VBOXSvga : lots of flickering with Windows Guests on Linux Hosts

[gojul]

Hi,

I tried the VBOXSvga driver with 3D support for the following guests :

• Windows VISTA
• Windows 7
• Windows 8
• Windows 10

I notice a lot of bugs, like Skype displaying a black window and more importantly transparency bugs and flickering. If I disable 3D support Skype remains buggy but flickering disappears. Now if I revert to VBoxVGA w/ 3D support enabled all is fine.

My host is as follows :

• Intel Core i7 4790
• 32 GB RAM
• NVidia GeForce 2070 SUPER w/ driver 430.40
• Debian Buster AMD64

I enabled the following environment variable as a workaround to the flickering bug we had w/ NVidia driver : CR_RENDER_FORCE_PRESENT_MAIN_THREAD=0

Perhaps is it the culprit, or is it something else ?

[Socratis]

Duplicate of #13653.

From comment #91 on that ticket:

On linux this Bug seems to be reintroduced with the "new" VBoxSVGA Graphics-Stack. I'm running VBox 6.0.4 on ArchLinux with an nVidia 1080 GTX and get the flickering even with CR_RENDER_FORCE_PRESENT_MAIN_THREAD=0.

which pretty much describes what you're filing as a new ticket...

PS. BTW, since you're using a mix of Capital and Lower case letters, it's VBoxSVGA, not VBOXSvga... ;)

[gojul]

My bad, I was aware of the previous bug but considered this one as a new one, as it does not affect the exact same component. Sorry for the disturbance.

[Socratis]

Hey, no problem. Most of my tickets (not here, in other fora) are usually duplicates! :D

[Klaus Espenlaub]

Closing this as a duplicate makes no sense whatsoever. The alleged duplicate is for a totally different 3D implementation (VBoxVGA as it is called today), and this additionally implies that the workarounds/hacks for the old code will not work any more.

[Socratis]

Replying to klaus:

True, very true, I got confused with the report from #13653 and the tie-in with the workaround. Mea culpa... :(

[gojul]

Issue still present with Virtualbox 6.1.4.

It is becoming an emergency to provide at least a workaround like the one that existed with VBoxVGA. Windows 10 guests are simply unusable. Office from 2013 onwards is completely unusable on Windows 8 and 10. And worse : you cannot avoid 3D acceleration in 8 and 10 guest in guest additions.

The only workaround consists in completely disabling 3D acceleration from host, which is not exactly acceptable.

[gojul]

It is *much* better with 6.1.6. Could not notice any glitch. The only remaining problem is with Windows 10 : everything that should be transparent is actually completely transparent, meaning there's no background at all. The control panel display is buggy as well. Could you please fix it as well, and everything's gonna be perfect ?

Thanks a lot !

[gojul]

Hi,

The issue still remains with Windows 10 - transparent bars absolutely transparent (no opacity at all) at least with the Windows 10 default theme. This is also problematic with the settings panel.